1. Field of Invention
The invention relates to a transport device for conveying printed products, wherein the transport device includes a conveying chain configured for a predetermined section and composed of a number of functional units that can be connected to each other.
2. Related Art
Conveying chains of this type are used for transporting printed products between individual processing stations, such as inserting machines, addressing units, adhesive-application apparatuses or the like. For this, the printed products are generally held in place by grippers mounted on the chain links and, if applicable, are released by these grippers at the processing stations. To ensure a continuous operation, the links of the conveying chain are normally driven so as to circulate continuously along the conveying section. The conveying chain is guided along the conveying section with the aid of suitable guide arrangements or guide rails which can also determine the curves of the conveying section. To ensure mobility along the conveying section, the chain links must be connected articulated, meaning so as to pivot independently around two axes, wherein the conveying section can have a length of 100 m or more. As a result, the installation of the guide rail arrangement and the chain links is correspondingly involved, wherein the articulated connection between the individual chain links must be ensured over the complete length of the conveying chain.
For the conveying chains described in Swiss patent document CH 588 647 A5, the installation of the chain links connected via spherical joints is to be facilitated by embodying the joint sockets and joint members as equatorial spherical segments. The idea of equatorially divided spherical segments is also picked up in Swiss patent documents CH 646 762 A5 and CH 656 683 A5. However, this type of design for articulated connections between individual chain links does not substantially facilitate the installation of the conveying chains on or in the guide rails.
Some degree of simplification is proposed for the installation of conveying chains as disclosed in Swiss patent document CH 593 187, for which the chain links made of plastic are detachably connected with the aid of pivoting axes and hubs that are oriented transverse to their longitudinal direction, wherein additional components are attached, so as to be detachable, to fastening elements of the chain links. However, the installation of the chain links on or in the guide rail arrangements or in the guide rails still presents considerable problems, even with the conveying chains described in this document. Somewhat easier is the installation of conveying chains as disclosed in U.S. Pat. No. 4,638,906 for which the individual chain links can be detached from each other by turning them around an axis extending parallel to the conveying direction wherein, however, the guide rail must be provided for this with corresponding openings.
The installation of a conveying chain as described in European patent document EP 1 832 532 A2 is to be made easier by having the bearing housing rest on two bearing housing parts which bridge a spherical bearing element to form a spherical joint. The idea of dividing the bearing elements into equatorial planes is again taken up in this document.
Finally, it is proposed in European patent document EP 1 557 387 A1 to make available cost-effective conveying chains by attaching to each link of the chain at least two clamps or grippers which respectively grip one printed product.
The above-provided explanations for the known chains used for conveying printed products show that considerable problems are encountered during the installation of said conveying chains along a conveying section which is predetermined by a guide rail arrangement while simultaneously ensuring a sufficient mobility for the conveying chain along a curved conveying section.